Welp, I had a feeling that 30 Keys(2 Buds at the time) was accurate before.

Sold for a Duped Haunted Ghosts Sergeant's Drill Hat(35 Keys with Overpay)*

http://backpack.tf/profiles/76561198097976497?time=1445151600 (October 18th)

http://backpack.tf/profiles/76561198097976497?time=1445583600 (October 23rd)

http://www.tf2outpost.com/item/440,4240088080,358,5 Knot History

*No useable duped sales or B/Os, being conservative with the current price.

Sold for 28 CS:GO Keys(~30-31 TF2 Keys)(B/O was 30)

https://gyazo.com/83664cebff5aa0513d2038c1401b2772

http://www.tf2outpost.com/trade/27253479

Two sales, 30-35 Keys should be fine.

Additional Proof/Counter-Proof/Constructive Criticism/Feedback is always appreciated.